Last January, as he prepared to offer the class again, Kelly put the Internet on notice. He posted his syllabus and announced that his new, larger class was likely to create two separate hoaxes. Hetold members of the public to "consider yourself warned--twice."

This time, the class decided not to create false Wikipedia entries. Instead, it used a slightly more insidious stratagem, creating or expanding Wikipedia articles on a strictly factual basis, and then using their own websites to stitch together these truthful claims into elaborate hoaxes.

One group took its inspiration from the fact that the originalStar-Spangled Banner had been sewn on the floor of Brown's Brewery in Baltimore. The group decided that a story that good deserved a beer of its own. They crafted a tale of discovering the old recipe used by Brown's to make its brews, registeredBeerOf1812.com, built a Wikipedia page for the brewery, and tweeted out the tale on their Twitter

feed. No one suspected a thing. In fact, hardly anyone even noticed. They did manage tofool one well-meaning DJ in Washington, DC, but the hoax was otherwise a dud.

The second group settled on the story of serial killer Joe Scafe. Using newspaper databases, they identified four actual women murdered in New York City from 1895 to 1897, victims of broadly similar crimes. They created Wikipedia articles for the victims, carefully following the rules of the site. They concocted an elaborate story of discovery, and fabricated images of the trunk's contents. Then, the class prepared to spring its surprise on an unsuspecting world. A student posing as Lisa Quinn logged into Reddit, the popular social news website, and posed an eye-catching question: "Opinions please, Reddit. Do you think my 'Uncle' Joe was just weird or possibly a serial killer?"

The post quickly gained an audience. Redditors dug up the victims' Wikipedia articles, one of which recorded contemporary newspaper speculation that the murderer was the same man who had gone on a killing spree through London. "The day reddit caught Jack the Ripper," a redditorexulted. "I want to see these cases busted wide open!" wroteanother. "Yeah! Take that, Digg!" wrote a third.

But it took just twenty-six minutes for a redditor to call foul, noting the Wikipedia entries' recent vintage. Others were quick to pile on, deconstructing the entire tale. The faded newspaper pages looked artificially aged. The Wikipedia articles had been posted and edited by a small group of new users. Finding documents in an old steamer trunk sounded too convenient. And why had Lisa been savvy enough to ask Reddit, but not enough to Google the names and find the Wikipedia entries on her own? The hoax took months to plan but just minutes to fail.